First sounds of the 18W TMB tremolo build

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Re: First sounds of the 18W TMB tremolo build

Post by JMPGuitars »

Bieworm wrote:
Tue 04/07/20 11:31 pm
ZP... then there's still the OD from zero on the vol dial. I don't think that this mod's a solution.
Don't shoot, but I don't need heavy distortion anyway. I never use it and if I do there are good pedal on my board to move in that direction. I am satisfied when I have a light amount of drive at 3-4 on the vol dial. I aim for the breakup point on that setting. Now maybe...just maybe... an adjustable NFB loop would bring solace? If it could act like my classic 18W, but with TMB tone abilities. Wouldn't it be possible? And as an extra I have no need for the ruby mod, since the OD will never get into that area?
Any info on the values of caps, resistors and pot?
How about the JA TMB version 2.0 ?
In theory this mod should reduce the gain, so maybe something else is wrong.

NFB is not the answer. It will kill the tone of the amp, and reduce the touch sensitivity.

Another option you have is to lower the second resistor (the one to ground) from the 470K/470K attenuator. You could try 330K or 220K and see what kind of results you get. If this reduces the gain, but you also feel you're lacking some of the highs, then do ZP's suggestion. Add a 100pF cap across the 470K series resistor.

You definitely need the Ruby Mod. I heard it in your demos. Installing the Ruby Mod could very well improve the way the amp works for you, and improve the distortion sound. Don't give up on it because it's hard for you to source (which it shouldn't be - you were looking at too high a wattage). Find a 1 watt 15V Zener diode. 16V or 14V would be fine too.
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Re: First sounds of the 18W TMB tremolo build

Post by Bieworm »

JMPGuitars wrote:
Wed 04/08/20 6:19 am
Bieworm wrote:
Tue 04/07/20 11:31 pm
ZP... then there's still the OD from zero on the vol dial. I don't think that this mod's a solution.
Don't shoot, but I don't need heavy distortion anyway. I never use it and if I do there are good pedal on my board to move in that direction. I am satisfied when I have a light amount of drive at 3-4 on the vol dial. I aim for the breakup point on that setting. Now maybe...just maybe... an adjustable NFB loop would bring solace? If it could act like my classic 18W, but with TMB tone abilities. Wouldn't it be possible? And as an extra I have no need for the ruby mod, since the OD will never get into that area?
Any info on the values of caps, resistors and pot?
How about the JA TMB version 2.0 ?
In theory this mod should reduce the gain, so maybe something else is wrong.

NFB is not the answer. It will kill the tone of the amp, and reduce the touch sensitivity.

Another option you have is to lower the second resistor (the one to ground) from the 470K/470K attenuator. You could try 330K or 220K and see what kind of results you get. If this reduces the gain, but you also feel you're lacking some of the highs, then do ZP's suggestion. Add a 100pF cap across the 470K series resistor.

You definitely need the Ruby Mod. I heard it in your demos. Installing the Ruby Mod could very well improve the way the amp works for you, and improve the distortion sound. Don't give up on it because it's hard for you to source (which it shouldn't be - you were looking at too high a wattage). Find a 1 watt 15V Zener diode. 16V or 14V would be fine too.
I found a supplier. So will be ordering them 15V 1.3W zeners.
But all that tweaking has made the amp noisy..sh*t! I can not find the problem. Chopsticked and resoldered everything that I've been tweaking but no result. When I start playing the noise goes away and I think it stays away. But when I switch the amp off and little later back on ..The noise is there again.
I will order new and better turrets + all the board components again and redo it. But first I want to be tweaked out... so I can built a neat and new board without the perspective of soldering on and off after that.
I pulled the preamp tubes and the noise is there too. Must be a connection somewhere...
This is a very vague description and I realise it can have a ton of causes ...But anything comes to mind?
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Re: First sounds of the 18W TMB tremolo build

Post by JMPGuitars »

Bieworm wrote:
Wed 04/08/20 6:38 am
I found a supplier. So will be ordering them 15V 1.3W zeners.
But all that tweaking has made the amp noisy..sh*t! I can not find the problem. Chopsticked and resoldered everything that I've been tweaking but no result. When I start playing the noise goes away and I think it stays away. But when I switch the amp off and little later back on ..The noise is there again.
I will order new and better turrets + all the board components again and redo it. But first I want to be tweaked out... so I can built a neat and new board without the perspective of soldering on and off after that.
I pulled the preamp tubes and the noise is there too. Must be a connection somewhere...
This is a very vague description and I realise it can have a ton of causes ...But anything comes to mind?
If you pulled the preamp tubes, and you still have the noise, then the noise isn't in the preamp.

When you rebuild, be sure to follow the latest layout (whatever that is at the time :wink:).

Post your current voltages, and a sample of the noise.
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Re: First sounds of the 18W TMB tremolo build

Post by Bieworm »

JMPGuitars wrote:
Wed 04/08/20 7:38 am
Bieworm wrote:
Wed 04/08/20 6:38 am
I found a supplier. So will be ordering them 15V 1.3W zeners.
But all that tweaking has made the amp noisy..sh*t! I can not find the problem. Chopsticked and resoldered everything that I've been tweaking but no result. When I start playing the noise goes away and I think it stays away. But when I switch the amp off and little later back on ..The noise is there again.
I will order new and better turrets + all the board components again and redo it. But first I want to be tweaked out... so I can built a neat and new board without the perspective of soldering on and off after that.
I pulled the preamp tubes and the noise is there too. Must be a connection somewhere...
This is a very vague description and I realise it can have a ton of causes ...But anything comes to mind?
If you pulled the preamp tubes, and you still have the noise, then the noise isn't in the preamp.

When you rebuild, be sure to follow the latest layout (whatever that is at the time :wink:).

Post your current voltages, and a sample of the noise.
I keep thinking it's the wire from V3 pin 2. Where it's connected to the .022 cap and 470k resistor I can hear noise when scratching with the chopstick. I already replaced that resistor tu rule that one out...
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Re: First sounds of the 18W TMB tremolo build

Post by JMPGuitars »

Bieworm wrote:
Wed 04/08/20 12:13 pm
JMPGuitars wrote:
Wed 04/08/20 7:38 am
Post your current voltages, and a sample of the noise.
I keep thinking it's the wire from V3 pin 2. Where it's connected to the .022 cap and 470k resistor I can hear noise when scratching with the chopstick. I already replaced that resistor tu rule that one out...
That's because you're guessing. See my comment above. ;)
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Re: First sounds of the 18W TMB tremolo build

Post by Bieworm »

JMPGuitars wrote:
Wed 04/08/20 12:18 pm
Bieworm wrote:
Wed 04/08/20 12:13 pm
JMPGuitars wrote:
Wed 04/08/20 7:38 am
Post your current voltages, and a sample of the noise.
I keep thinking it's the wire from V3 pin 2. Where it's connected to the .022 cap and 470k resistor I can hear noise when scratching with the chopstick. I already replaced that resistor tu rule that one out...
That's because you're guessing. See my comment above. ;)
Josh I was right. I removed the cap, resistor and wire from the turret. Cleaned it from solder and rewired. Sounds way better. If it wasn't the cause of it, it sure didn't help. There were little pieces of wire leftovers in the solder I think. But it's way better now.

Even the pop when switching the amp off is gone...that was one effect of the malchanges too..
Last edited by Bieworm on Wed 04/08/20 1:41 pm, edited 1 time in total.
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Re: First sounds of the 18W TMB tremolo build

Post by Bieworm »

New voltage chart:
15863711773083414959812145982417.jpg
We'll see...
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Re: First sounds of the 18W TMB tremolo build

Post by JMPGuitars »

Bieworm wrote:
Wed 04/08/20 1:28 pm
Josh I was right. I removed the cap, resistor and wire from the turret. Cleaned it from solder and rewired. Sounds way better. If it wasn't the cause of it, it sure didn't help. There were little pieces of wire leftovers in the solder I think. But it's way better now.
Well, that makes sense. You need to keep your connections clean. If you can get a proper desoldering gun, that will make your life easier. My soldering station has one built in, so I find it easy to rework things.

You could try your luck with some de-soldering braid, or a desoldering pump, but they take more effort with less ideal results.
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Re: First sounds of the 18W TMB tremolo build

Post by Bieworm »

JMPGuitars wrote:
Wed 04/08/20 1:55 pm
Bieworm wrote:
Wed 04/08/20 1:28 pm
Josh I was right. I removed the cap, resistor and wire from the turret. Cleaned it from solder and rewired. Sounds way better. If it wasn't the cause of it, it sure didn't help. There were little pieces of wire leftovers in the solder I think. But it's way better now.
Well, that makes sense. You need to keep your connections clean. If you can get a proper desoldering gun, that will make your life easier. My soldering station has one built in, so I find it easy to rework things.

You could try your luck with some de-soldering braid, or a desoldering pump, but they take more effort with less ideal results.
An amateur like me obviously has the pump ;)
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Re: First sounds of the 18W TMB tremolo build

Post by JMPGuitars »

Bieworm wrote:
Wed 04/08/20 2:39 pm
An amateur like me obviously has the pump ;)
lol, I don't miss those days. But try adding a drop of solder while you heat up the turret. That might help the pump do its job.
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Re: First sounds of the 18W TMB tremolo build

Post by Bieworm »

JMPGuitars wrote:
Wed 04/08/20 2:55 pm
Bieworm wrote:
Wed 04/08/20 2:39 pm
An amateur like me obviously has the pump ;)
lol, I don't miss those days. But try adding a drop of solder while you heat up the turret. That might help the pump do its job.
https://www.dropbox.com/s/g6i9j0pbygiq1 ... 6.m4a?dl=0
Darn...
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Re: First sounds of the 18W TMB tremolo build

Post by JMPGuitars »

What happens when you tap the filter caps with a chopstick? If you get a loud pop or click noise, they're probably bad. But if that's not the case, they might need to be soldered better.

...and if that's not it, you might be searching for a cold solder joint somewhere else. That's my guess anyway. ;)
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Re: First sounds of the 18W TMB tremolo build

Post by JMPGuitars »

BTW- I just updated the layout. It should make for a quieter / cleaner build.
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Re: First sounds of the 18W TMB tremolo build

Post by Bieworm »

JMPGuitars wrote:
Thu 04/09/20 4:30 pm
BTW- I just updated the layout. It should make for a quieter / cleaner build.
looks nice!
yesterday I tried the 10k resistor to ground at the bifurcation of the normally 2x 470k from V2 pin 7. That was clean allright. But also the low disappeared and the amp sounded boxy like a f*nder champ ;)
So I tried different values (220k and 100k)
The 220k was still little grindy, but much less than the 470k. The 100k was really clean, but also too thin.
Was thinking of putting a 500k pot to replace the resistor to ground. Are there remedies to bring back the low end across the pot or resistor? Would a parallel cap such as a .022uf be a 'cure'? In that case I would considder this the clean/drive knob. Maybe even make it footswitchable between the pot and another 470k resitor?

concerning the noise... tonight I will be rewiring the input jack. I had this kind of noise on my vibrolux and it turned out to be the connections on the input jack. Does that make sense, considdering the noise being there even with the preamp tubes removed?
Or what area should I be scanning for default?

For the filter cap tapping...I didn't get any weird noises doing that (I did this already before). But on my classic the .022 or the .01 cap coming from V2 (PI) pin 2 or 7 make a hollow amplified sound when popping them with a chopstick. I thought that was normal? Is that normal or should caps never make any sound?

And something strange happened to the voltages on the PI tube V3. Pin 1 has 219V which is ok, but pin 6 measures 202V. Is this a normal consequence of lowering the resistor to ground on pin 7 V2?
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Re: First sounds of the 18W TMB tremolo build

Post by Bieworm »

Bieworm wrote:
Thu 04/09/20 11:46 pm
JMPGuitars wrote:
Thu 04/09/20 4:30 pm
BTW- I just updated the layout. It should make for a quieter / cleaner build.
looks nice!
yesterday I tried the 10k resistor to ground at the bifurcation of the normally 2x 470k from V2 pin 7. That was clean allright. But also the low disappeared and the amp sounded boxy like a f*nder champ ;)
So I tried different values (220k and 100k)
The 220k was still little grindy, but much less than the 470k. The 100k was really clean, but also too thin.
Was thinking of putting a 500k pot to replace the resistor to ground. Are there remedies to bring back the low end across the pot or resistor? Would a parallel cap such as a .022uf be a 'cure'? In that case I would considder this the clean/drive knob. Maybe even make it footswitchable between the pot and another 470k resitor?

concerning the noise... tonight I will be rewiring the input jack. I had this kind of noise on my vibrolux and it turned out to be the connections on the input jack. Does that make sense, considdering the noise being there even with the preamp tubes removed?
Or what area should I be scanning for default?

For the filter cap tapping...I didn't get any weird noises doing that (I did this already before). But on my classic the .022 or the .01 cap coming from V2 (PI) pin 2 or 7 make a hollow amplified sound when popping them with a chopstick. I thought that was normal? Is that normal or should caps never make any sound?

And something strange happened to the voltages on the PI tube V3. Pin 1 has 219V which is ok, but pin 6 measures 202V. Is this a normal consequence of lowering the resistor to ground on pin 7 V2?
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